By way of background, the use of machine vision systems to inspect the quality of manufactured containers is well known in the art. For example, U.S. Pat. No. 4,882,498 entitled “Pulsed-Array Video Inspection Lighting System” discloses the use of an engineered solid-state illuminator in automated container inspection systems, an improvement to the prior art. Additionally, the extension of automated inspection equipment to include the function of correlating container defect information to specific machine entities used in the manufacturing process is evident in the existing art. As an example, U.S. Pat. No. 5,591,462 entitled “Bottle Inspection Along Molder Transport Path” describes an inspection system for molded plastic or PET containers that identifies container defects and allows those defects to be directly related to a machine entity associated with the containers formation. In this system, container defects can be correlated to the mold cavity, machine transfer arm, or machine spindle used to form a specific bottle. This invention achieves the correlation function by way of its close physical coupling to the manufacturing process. The vision system is installed within the bottle molder and a series of proximity or photo-eye sensors are used by the inspection system to keep track of bottles and the machine entities used to form or handle them.
Also in the area of automated inspection of molded containers, U.S. Pat. No. 5,926,556 entitled “Systems and Methods for Identifying a Molded Container” describes a system wherein a machine-readable code is included in the bottom portion of a molded container during the process of container formation. The code uniquely identifies the mold of origin of the container. This machine-readable code is viewed downstream of the molding operations by an automated inspection system after they have been serialized by the material handling system used in a particular plant into a single randomized stream of containers. This prior patent relates specifically to a system for molded containers and contains no specific provision for integrating the code reading function of a machine vision system, for reading codes stamped in metal containers, with a parallel defect detection functionality. The codes disclosed by the prior patent do not include a fiducial. Also, because molded containers are described in this prior patent, there is no provision for determining the source of origin of the container relative to different machines, as opposed to mold cavities, that form the containers.
The present invention addresses these concerns and others.